Air operated impact press



Sept. 16, 1952 w. BRYANT AIR OPERATED IMPACT PRESS 2 SHEETSSHEET 1 Filed Dec. 23, 1947 7 4. 5 3 m l P /J// V II T V Q WT H A u n a J m.

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AIR OPERATED IMPACT PBESS Filed Dec. 25, 1947 2 SHEETS-SHEET 2 a2\ 33 28 I2 ,42 a

Y a f n/ 23 j 26 2 2o 5 24 29 2a 3- FJE LIZ HAY WEE mm? m ila Patented Sept. 16, 1952 .1; t":

Ray w. Bryant, Jackson, Mick, assigner to in} Hydraulics, IncnJack'son, Mich., a corporation v of Michigan Application December 23, can, seem mxnaiii This invention relates to pneumatic power rm pact press, hammer, riveter, die or the lik'e 'mv chines of the kind which comprise a pneumatic cylinder and piston operated 'bythe air pres'-' sure and carrying the operating part by which the desired impact action is applied: I

It is an object of the present invention to pro vide an 7 improved yet simple construction of pneumatic impact powe'r'press or the like of the above character lwhich is highly efiicient and is capable or operating with an extremely high im= pact characteristic, v

It is a further object or the invention to provide a pneumatic impact power press; hammer, rlveter or the like in which the required impact action is obtained'with the use of a reservoir in which the energy or a body of compressed air is always storedeu'p readyfor useas and when desired, by the actuationof a simple release valve means which permits" this body of pressure air to exert an explosive l-ike action upon the impact producing member, either directly or iii-- directly.- r i a The apparatus in accordance-with the invem' tion therefor is distinguishable from known pneumatically actuated impact power presses which depend upon-air pressure continuously supplied through a port to produce thedesired impact 1 Claim. (01. 121 -38) motion" since, with the apparatus provided by this invention, it is" the stored up energy alwayspresent in the said reservoir which is'utilized to produce each impact action. 1

The above and other objects and advantages or theinvention will appearclear-from a con-' sideration of the following description with ref erence to one embodiment of'the invention as illustrated in the. accompanying drawings in which:

' Fig.1 isza longitudinal section of-onee'mhodl ment of theinvention, with the piston power stroke; a -v Fig. IIisan:elevational;vlewofrl igrl, Fig. III is a section on the line III-=III- of Fig; ILv-an'di Fig. IV is a: section .o'n'the 1ine 1v -"-Iv'or-F1g. III. In. carrying the invention into effect in one convenient manner as illustrated in the draw ingspneumatic apparatus is provided, comprising a. cylinder I having a" head plate-2 and aset fora base plate 3 and housing adouble acting piston 1 4 connectedwith a plunger rod 5 which 'i's-qr larger diameter than another plunger rod 6, which plunger rods are mounted for reciprocatio'n through openings inth'e head'plate and the" pass plate. The one lunger rod 6 servesfor the" attachment at its iawipeha 'ofa iv tin h ad. L i r t pa t he 16 anon bf which it 'is desiredshould talile ace witha hammer-like action underthe influence "of the pneumatic energy employed. 1 a I a 7 H The differential diameters "of theplung'ei; rods result in the piston presenting diiierential an}? i'ilular piston surfaces on its bpposite faces, of which the annular piston surface! presents", a smaller s urracearea than the annular surface 8, which presents the largest surface area. l ne/fleas plated ha a per; a con ection In may e made for admitting pres swear to the cylinder space ll qhmqssap tweenthe smaller piston surface; rand the head face 8 and the base plate 3.

The pressure air to both ylinder spaces is suppned from a e mmon source, auras n an compres or, arr-dis conveniently distributed t6 the two cylinder spaces througl'ia pipe hook? up consisting or the T l4, connection [0 andthe' pipe I 5, the T being itselrrconnected to the ma pressor, and the pipe l5 conducting the pressure air from the -r to a port [6 (Figs. n an n) in the base plate 3, which port [8, and also a laterally adjacent andspac'edport 11, are under the. control of a piston valve i8. l a v y v This piston valve is reciprocable within a holf low cylindrical portion IS formed in the case plate 3 and divides such cylindrical portion into two cylinder spaces 20 and 2 I, of vvhichthe space 20, i the pos'ition of the piston valve l8 as seen I in Fig; III, connects the port lfiwith an exten' sion 2 of the cylindrical space zfl, which as: tension is open to the port I2; ,The other cylin .der space 2| contains the port I! by'which pres sure medium (normally compressed airXCanIb'e introduced into this cylinder space" under the controlof a multi or three way pilot valve 39, shown diagrammatically in Fig. II. Also the piston 18, constituted by a se'aling ring' 23 located an annular" space formed between axially spaced flanges 24', has a reduced piston portion 25 connected with an axially spaced head v26 means of' an intermediate connecting shank" 21 of spider rormation' as shown in Fig. I in par: ticular, this connecting" shank Being formed y axially ei'rtending radial vi'iebs' drfiii 2B which afiord a clear passageway between them far the? new gr me pressur'e'aii between the ports is and the larger" piston stir;

der space 29 containing an exhaust port 30. Both the reduced piston portion 25 and the head 26 are fitted with sealing rings 3i and 32 respectively for maintaining sealing contact with the opposed annular end wall surfaces 33 of their respective cylinder spaces.

The piston 4 is also conveniently formed by a pair of axially spaced flanges 34 forming an annular space between them in which a sealing or O ring 35 is located. The plunger rods 5 and B may also operate past sealing or rings 36 in their respective end bearing plates 2 and 3.

A coil spring 3'! mounted about the plunger rod and hearing at one end against the piston face "I and at the opposite end against the inside surface of the end plate 2 serves to maintain the piston 4 normally in predetermined spaced relationship from the end plate 2, whereby to provide that the cylinder space H is of a certain normal area or size.

Another coil spring 38 mounted about the plunger rod '6 and bearing at one end against the inside surface of the base plate 3 serves as a buffer or cushion spring. 3

With the construction as thus described and as shown in the drawings, pressure air can be admitted from the common supply source (normally an air compressor) into the two cylinder spaces I I and I3, the passage of the pressure 'air into the cylinder space I3 beingpossible. due to the fact that the piston valve I8 is shown positioned to leave the port I6 open to the cylinder spaces 23, 22 and henceto the port I2. "The differential areas of the piston surfaces 1 and 8 provide that in this condition of the piston valve I8 and its connected parts, the piston 8 is held in a raised ,position,.as shown in Fig. I, against the action of the coil spring 31, the latter acting ,merely as a spacer to cause a measured space or area to exist above the piston 4, this space being constituted by the cylinder space II and being filled by the compressed air delivered through the port 9 at the same time as thecylinder space I3 is filled with the compressed air delivered through the ports I3 and I2.

v With the apparatus thus set, in order to produce an operative stroke of the plunger rod 6, and thereby to produce the required hammer, riveting, or like impact action, the pilot valve '39 is adjusted to permit pressure air to enter the cylinder space 2I through the port I"! and thereby push the piston valve I8 tothe left, as seen in Fig. III, to a position in which the port I6 is closed by the piston valve and the sealing ring 3I is in contact with the annular cylinder end wall 33. With the piston valve so set the supply of compressed air to the cylinder space I3 is cut off, while simultaneously therewith the packing 32 of the valve head 26 is unseated from the cylinder surface 33, and thus opens the cylinder space I3 to the outer atmosphere via the ports I2, cylinder extension 22 and exhaust port 30. l It may be pointed out here that the diameters of the ports I2 and 30, including also that of the cylinder extension 22, are relatively large and offer no resistance to the flow of the air, whereby upon the piston valve head 26 being moved to the open position the compressed air previously enclosed within this cylinder space I3 is exhausted in a flash. It should also be pointed out that the cylinder space I I is always charged with a supply of the compressed air and accordingly, in the elevated condition of the piston 4, always has the energy of this body of compressed air storedup therein. Accordingly. when the cylinder space sible, what I claim as novel is; J

4 I3 is exhausted this stored-up energy of the bod; of the compressed air within the enclosed cylinder space II operates with an explosive-like action upon the piston 4 and thereby causes the piston rod 6 to travel at high velocity and accelerated motion through the base plate 3 and results in the obtaining of an extremely high impact characteristic. The actual speed of operation can be regulated by the connection of a control valve with the exhaust outlet 30.

In the event that the desired operative impact is not effected beforehand, the arrival of the piston 4 at the coil spring 38 will permit this spring to come into effect to cushion the piston motion and thereby prevent undue damage by impact of the piston with the base plate 3.

To re-set the apparatus for another operative cycle the pilot valve 39 is adjusted to exhaust the air from the cylinder space 2I and thereby permit the pressure air at the inlet port I6 to push the piston valve I8 to the right, into the position shown in Fig. III, the piston valve head 26 being at the same time closed, as shown. In this position of the piston valve I8 and its head 28 the cylinder space I3 is filled with the compressed air and the piston 4 is ready for another power stroke. a

It will be seen that with the existence ofthe difierential piston surfaces I and 8 equal air pressure within the cylinder spaces I I and I3 will result 'in the piston beingheldin a raised position as shown in Fig. I, both cylinder spaces being then filled with the pressure air. It will also be appreciated that the valve mechanism provided, that is, the pilot valve 39 and the piston valve I8 with its connected valve head 26, permits the cylinder space I3 to be alternatively exhaustedand filled with air atthe same high pressure. as that in the cylinder space II, which latter at all times filled with the pressure air. 7 7

Having thus described my invention and one practical embodiment thereof, 'it being understood that other practical embodiments are pos- A'pneumatic power impact machine tool com prising a cylinder having air line pressure con-1 nections at opposite ends, a piston in said cylinder for reciprocation therein by differential air pres,

sure on opposite sides thereof, closure structure for the ends of said cylinder havingrapertures therein, rods of different diameter extending from opposite sides of saidpiston axially ofsaid cylinder through said apertures to provide said cylinder with differential effective surface areas upon opposite sides thereof, a coiled compression spring embracing the rod of larger diameter and dis posed between said piston and the closure struc-v ture for one end of said cylinder to space said piston from one end of said cylinder'to. provide a storage chamber for air pressure and to store up energy against the side of said piston of lesser,

effective area, a similar spring embracing said rod of smaller diameter to act as a buffer upon being engaged between said piston and the closure structure for said cylinder, conduit structure attached to said connections for simultaneously conducting air under said line pressure tosaid cylinder upon opposite sides of said piston to move said piston into a position compressing said spacing spring due to said differential efiective surface areas, exhaust structure for the rapid removal of air pressure from the end of said cylinder in which said buffer spring is disposed, and valve means associated with said conduit and exhaust structure for exhausting airfrom one side of said piston only to enable the air pressure in that portion of the cylinder in which said spacing spring is located to rapidly expand and move said piston, aided by the stored ener y of said spacing spring, to impart high velocity movement to said piston into engagement with saidbuffer spring, that portion of said conduit structure connecting with said storage space continuously connecting line air pressure with said storage space.

RAY W. BRYANT.

REFERENCES CITED The following references are of record in the file of this patent:

Number 6 UNITED STATES PATENTS Name Date Humphrey Dec. 12, 1899 t Rumold Jan. 28, 1913 Lower Feb. 26, 1918 Trace Apr. 6, 1920 Weirich Aug. 30, 1927 Ring Jan. 25, 1938 Raiche Nov. 23, 1943 

